No abstract

L-Phenylalanine (L-Phe) sensors were prepared with two steps by modifying the Pt electrode using the molecular imprinting technique. In first step, polymeric films based on p-toluene sulfonic acid (PTSA) were electropolymerized on the Pt electrode in the presence of L-Phe as template molecule. In the second step, L-Phe, the template molecule, was desorbed from the film structure coated on the electrode surface using acid. The surface properties and morphologies of the prepared modified electrodes were checked by SEM analysis technique. These modified electrodes were used for determination of L-Phe by differential pulse voltammetry (DPV). Electrodes obtained by molecular imprinting method showed R2 = 0.9997 in the concentration range of 2–2000 μM L-Phe. The limit of detection (LOD) of L-Phe selective electrodes was found as 0.59 μM and the limit of quantification (LOQ) was 1.77 μM. The first three repetition result with the same modified electrode was observed as 96.83% and the RSD value was 14.96% for ten replicates. For twenty modified electrodes, reproducibility was obtained as 97.67% stable between first electrode and twentieth electrode, and the RSD value was observed to be 2.33%. According to these results, prepared molecular imprinted electrodes have high repeatability, stability and selectivity for the determination of L-Phe.